Action to secure both sides of dragline crane, maybe (5)
I believe the answer is:
wader
'crane maybe' is the definition.
(crane is a type of wading bird)
'action to secure both sides of dragline' is the wordplay.
'action' becomes 'war' (military action).
'to secure' is an insertion indicator (inserted letters are secured inside).
'both sides of' says to hollow out the word (remove centre letters) (only the letters on the sides remain).
'dragline' with its middle removed is 'de'.
'war' enclosing 'de' is 'WADER'.
(Other definitions for wader that I've seen before include "High waterproof boot" , "Eg, sandpiper, flamingo" , "Eg, sandpiper or plover" , "Long-legged shore bird" , "Type of long-legged bird" .)